Crashworthiness analysis of shrink circular tube energy absorbers with anti-climbers under multiple loading cases

Abstract

Energy-absorbing structures with anti-climbers for railway vehicles rarely experience pure axial loading in real crash events, but rather a combination of axial and off-axial loads. In this perspective, it is critical to understand the non-centric collision process of energy absorbers. To address this issue, this paper aims to investigate the crashworthiness of shrink circular tube energy absorbers with anti-climbers under vertical, horizontal eccentric and oblique loads comprehensively. Finite element (FE) models of the shrink circular tube energy absorber with anti-climbers are then developed and validated by a physical impact experiment. The numerical results show that the different eccentric distances and oblique angles affect the crashworthiness of the proposed energy absorber significantly. The energy-absorbing structure exhibits a stable and controlled deformation pattern as well as a very high energy absorption efficiency in offset collisions at different vertical heights. However, when the horizontal offset distance exceeds half of the anti-climber width, the energy-absorbing circular tube suffers an overall destabilizing deformation, failing in the energy-absorbing capacity. Additionally, the proposed energy absorber is suitable for oblique load collision scenarios that the oblique angle is no more than 10°. Finally, the response surface modeling technique and non-dominated sorting genetic algorithm are employed to optimize the key structural parameters of shrink circular tube energy absorbers under multiple loading cases. The results exhibit that an optimized shrink circular tube energy absorber is more competent in crashworthiness for multiple load cases.

Keywords:

• Shrink circular tube
• eccentric impact
• oblique impact
• anti-climbing
• optimization

Declaration of competing interests

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Additional information

Funding

The authors gratefully acknowledge financial support from the National Natural Science Foundation of China (grant no. 51975588) and the Science and Technology Innovation Program of Hunan Province (grant no. 2020RC1001).